The present invention relates to a thermally conductive electrochemical sensor.
Electrochemical biosensors are well known. They have been used to determine the concentration of various analytes from biological samples, particularly from blood. Electrochemical biosensors are described in U.S. Pat. Nos. 5,413,690; 5,762,770 and 5,798,031; as well as in International Publication No. WO99/13101, each of which are hereby incorporated by reference.
An electrochemical biosensor typically includes a sensor strip and a sensor instrument. The sensor strip includes a space that holds the sample to be analyzed, may include reagents to be released into the sample, and includes an electrode set. The electrode set normally includes an insulating substrate, and electrodes that contact the sample, which have contact pads for electrically connecting the electrodes to the sensor instrument.
The temperature of the sample during analysis will effect the signal detected by the electrochemical biosensor. In order to compensate for variations in sample temperature, most electrochemical biosensors measure the ambient temperature, typically by using a temperature sensor in the sensor instrument, and contain electronics for electrochemical analysis. The temperature of the actual sample may vary from the ambient temperature, depending on the humidity and local air movements, by three degrees, or more. Furthermore, the ambient temperature is not necessarily stable, and therefore algorithms have been used to compensate for changes in ambient temperature (see, for example, U.S. Pat. No. 5,405,511, hereby incorporated by reference). In addition, if the instrument is held in the hand during use, the recorded ambient temperature may be effected by the temperature of the hand.
None of these devices actually measures the temperature of the sample, but rather simply use the ambient temperature measurements to indirectly determine the temperature of at the sample site, or the temperature close to the sample. It would be desirable to more accurately measure the temperature of the sample, thus avoiding the need for compensatory algorithms, and improving measurement accuracy.